I have a really bad problem with my 89 Formula 350, it does not start after it is warmed up. I would go somewhere and the car will leave me stranded for minutes even hours. All the gauges work and the fuel pump primes but the car wont crank, nothing. I have changed almost everything on this car. I have even put a heat sheild on the starter and the car still leaves me stranded. I have changed the starter and silenoid, the ECM, starter silenoid module, the ignition switch and key, the pass key decoder module, and the neautral safety switch. Does anyone have any Idea what it could be???? Does it mean that I need a new car. I need help really bad or a miracle.

 

When you say the car won't crank are you saying you turn the key and nothing happens? If so, you either have a bad VATS key or a weak fusible link that gives you trouble when warm. You have covered most of the possible causes. Before I ramble on with other possibilities, answer the above.

 

yes i turn the key and it does not start, key is new

 

Common problem, I used to get stranded too, till it cooled down enough. Heat soak on the celinoid is probably the cause. When the car gets really hot, the resistance of the heat exposed wiring goes up, therefore you need more juice then when cold to get the starter to engage.
Here is a simple trick that you can use to keep you from getting stranded that has worked for me for a long time. Be careful if you have a manual though, make sure you are in nutural with the parking brake on:
1) Get under the car and locate the purple wire going to the celoniod. Loosen the nut holding it on.
2) Take a spade shaped wire connector of the proper size to slide in there and connect a medium guage wire to it, about the thickness of the cord of your PC Mouse.
3) Secure the wire to the celonoid and run the wire all the way up to the battery and clip it.
4) Strip the end and cap it off with a wire connector
5) Test the solution, go in the car and turn the igniton to ON (make sure your in netural if manual)
6) Walk over to your wire and touch the stripped end to the POSITIVE terminal on the battery.
7) VROOOMM. Re-cap the wire, Close the hood and off you go.

 

That is somewhat ghetto, although functional. A safer and more permanent way to fix this normal third gen curse is to use a remote starter relay (as used by F*rd) it should fix your problem permanently and it is a good upgrade anyway.

 

i did put a toggle switch and wire to the purple wire to start it when it does not start, but to me that tells me that its not the starter or silanoid does not need to be replaced so it has to be the wiring